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Sys2k in new home, dripping from relief valve, water hammer, 0 pressure cold, help!

JLacoyJLacoy Member Posts: 8
So we just moved into a new home 3 months ago, just getting into the heating season now and running into issues. I worked previously (15 years ago) as a service tech/install monkey for an oil company, so not flying completely blind here. First time poster here though!

System 2000 oil fired
3 heat zones (2 on first floor, 1 on 2nd floor)
Indirect hot water 40g storage tank (plate exchanger off boiler)
Horizontal mounted pressure tank, (hot on top, cool on bottom, assuming bladder is still intact) air relief valves on both supply and return side of boiler
No good means of manual air elimination/purging the zones via drains on the individual zones (my preference)

So the pressure relief on the boiler had been incessantly leaking, and I had kept the auto water feeder manually shut off, and topped it off every few days. Crud gets in the valve, and it drips, nothing new. Replaced the valve, no help, kept dripping. Dialed back the set pressure on the auto water feeder to 10psi. If I leave the feeder valve off, cold, the system sits at 0psi, and then begins to develop water hammer in the 2nd floor zone. No drips.

If I leave the feeder valve on, system cold sits at 10psi, and immediately blows off at 30psi as its coming up to temp. Frankly, I'm kind of stumped. Everything seems to be in working order and functioning individually, just as a whole, something is throwing it off, cant find the happy medium.


  • Jamie HallJamie Hall Member Posts: 12,855
    That sort of behavior can only happen, really, if the expansion tank is not functioning. It could be that the precharge is incorrect (should be checked with tank empty, isolated, and should be at your cold set temperature). Could be that the tank is waterlogged. And could also be... are there any valves between the pressure tank and the system which might be closed? Sounds silly, but we've all done things like that!
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • SuperTechSuperTech Member Posts: 1,336
    edited December 2019
    That doesn't look like a very good installation of such a high quality boiler. I really don't like the horizontal expansion tank, that's not right. Threaded connection should be facing up. Also it's critical that the cap on the air vent on the boiler is left open, or off at all times. You can contact EK directly if needed, their customer service and technical support is second to none.

    I've worked on a lot of EK boilers and I have never seen anything like that before. I don't think they followed the manufacturers installation instructions.

    I really hope that they performed a combustion analysis with a digital analyzer, it's critical that the burner runs at a minimum of 6.5 percent O2
  • JLacoyJLacoy Member Posts: 8
    @Jamie Hall Yeah, without pulling it apart before our first snow storm this afternoon, my next suspect was the expansion tank. Considering just running a long nipple over to a 90 with some pipe hanger and putting it off the side of the boiler, not to interfere with the cleanout.

    I have to assume something changed at some point, for this to not be a chronic issue. There was evidence of water around the base of the boiler, but I traced that back to dry rotted circulator flange gaskets which I remedied.

    Its like a car, I hate to throw money at it just replacing parts without diagnosing the root cause, but the expansion tank is an easy fix if need be.

    @SuperTech , the air vents are not capped off. They are bleeder caps, and I do indeed only have them threaded on a few turns as to not block them.

    I'm going to read through the installation manual, so I'm curious if this is the recommended design, but the expansion tank/relief is only on the boiler, and completely seperate from the heating zone loops, using just one of the small front and one of the top tappings on the boiler where the aquastat is installed.

    Should I try and get the expansion tank installed somewhere inline with the S/R manifolds? Or do I really need it isolated to the top of the boiler.

  • JLacoyJLacoy Member Posts: 8

    I certainly overcomplicated that. Put a pressure gauge on the expansion tank, 0 pressure whatsoever with the system even under pressure and running at temp.

    Tank is probably full of water, and only the top is getting warm due to convection and the horizontal mounting. Guess we'll give that a go!
  • HVACNUTHVACNUT Member Posts: 3,356
    > @SuperTech said:
    > That doesn't look like a very good installation of such a high quality boiler.
    > I've worked on a lot of EK boilers and I have never seen anything like that before. I don't think they followed the manufacturers installation instructions.
    That's a first generation EK-1. Different design. Rear HX access.
  • JLacoyJLacoy Member Posts: 8

    @HVACNUT , I'l probably revamp it a bit next spring once we get through the heating season. For now, to just make it functional!
  • HomerJSmithHomerJSmith Member Posts: 923
    My eyes are getting bad. I don't see an air separator. Maybe it is hidden.
  • JLacoyJLacoy Member Posts: 8
    @HomerJSmith, it's not there, they half assed it and just put a few air vents on a few high spots on the boiler. I moved to NH, not sure what exactly is ever looked over by local inspections to get signed off on. Home appears to have been reno'd 5-6 years ago between owners.

    I'm not planning on making a career out of my home heating system, but I'll tune it up next year, probably move the manifolds to the wall and make it a bit more 'user friendly'.
  • HomerJSmithHomerJSmith Member Posts: 923
    Air vents ain't going cut it. You need an air separator, like Caleffi or a Honeywell air separator. The air vents are to remove air at the high points, they don't scrub the water of oxygen which is extremely harmful to any sys with cast iron components.
  • HVACNUTHVACNUT Member Posts: 3,356
    > @JLacoy said:
    > @HVACNUT , I'l probably revamp it a bit next spring once we get through the heating season. For now, to just make it functional!

    I wasn't knocking it. Just for @SuperTech to know it's an EK model he might not have seen.
  • HomerJSmithHomerJSmith Member Posts: 923
    edited December 2019
    Next to the Expansion Tank is a chrome Taco HyVent, air vent. What's that brass fixure next to the HyVent that has a 90 deg turn leg?
    Do you see all that rusty water that came out of the air vent above the tridicator gauge. That rusty water that dripped from the old air vent all over your pump is what's circulating in your sys. Oxygen creates rust on any ferrous part.
    Rust will also wear out the ceramic bearings in your circulator.
  • JLacoyJLacoy Member Posts: 8
    @HomerJSmith, tank was bad, just swapped it. Was going to hang it but couldn't get the old bushing out and didn't have the right size copper x male adapter.

    The part next to the hi vent is the pressure relief valve. First part I swapped, figuring it was gummed open with corrosion.

    Didn't know that about the air scoop, will certainly be addressing that sooner rather than later! Preferably installed on the supply or return side?
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